Adhesive sheet material



Sept. 15, 1936. F. H. RUSSELL 2,054,448

ADHESIVE SHEET MATERIAL Filed D60. 29, 1952 Patented Sept. 15, 1936 ADHESIVE SHEET MATERIAL Frank 1!. Russell. Needham, Mm, assimiof one-half to Dewey and Almy Chemical Company, North CambrldgegMaoes and one-half to Peppereli Manufacturing Company, Boston,

\ Mau.,acorporationofMauaclmaetts Application-December. so, 193:. Serlai'No. $49,340

7 Claim.

This invention relates to the application of adhesive compositions to flexible sheet material and generally comprises the use of a notched or serrated doctor blade to afford a more desirable distribution and deposition of the adhesive substance upon the flexible base material,

a machine, a process, and a product thereof, all as more fully hereinafter described and claimed. In the preparation of flexible adhesive sheet material such as surgical tape, masking tape, gem duck, and similar .productsfit' is common practice to flow or deposit the adhesive upon the flexible base material, which may be paper, felt, woven fabric, or the like, and then to remove any undesired excess by means of a doctor blade which may scrape close to the surface of the sheet material or may operate to leave anadhesive layer of substantial and predetermined thickness. This general procedure yields operatively satisfactory results when relatively thin or fluid adhesive compositions are employed; but it presents greater difficulties for use with viscous materials which tend to ball up before the doctor blade and refuse to pass beneath it to produce a smooth and uniform thin coating of desired thickness upon the flexible base material. An object of this invention is to provide a de ice which will yield a more desirable depositio and distribution of viscous adhesive on flexible sheet material than has existed heretofore. Another object is to afford a more convenient and satisfactory process for applying adhesives to flexible sheet material than has been available previously. Still another object is to provide flexible adhesive sheet material which possesses improved properties over the materials formerly prepared. Yet other objects will become apparent as the description proceeds.

I have discovered that the foregoing objects are attained and new advantages accrue if viscous adhesive compositions are applied to flexible sheet material with the aid of a notched or serrated doctor blade. In the drawing, Figure 1 illustrates 'one form of my new device. It differs from the usual straight edge doctor blade by the plurality of notches or serrations shown at i. These may have a V, rectangular, or semicircular shape; and depending on the purpose at hand, I generally prepare them from $4; to V inch apart and from 1/64 to inch deep. Adhesives which are very viscous require larger and more widely spaced notches than those which are more fluid. Figure 2 shows a prenature of the adhesive composition and/or the use to which the adhesive sheet material is tobe subjected. 'Figure 3 shows the way in which my device may operate in combination with a usual time of "gem duck machine. It may be adjusted so that the straight edge portions between the notches scrape close to the base material, or,,when a thicker layer is desired, so

that the straight edge portions function to addust the thickness of the adhesive composition to a predetermined depth. .Those skilled in the art will appreciate, however, that my notched blade is equally well adapted for use in combination with other types of machines for applying adhesive compositions to sheet material. Figure-4 illustrates-a cross section of a strip of flexible adhesive sheet material which has been made according to this invention and shows the coating of viscous adhesive existing in two different thicknesses so as to form a series of grooves or striations illustrated at 2 in the coating layer.

Aside from its more general advantages, this invention possesses certain special advantages for use in connection with the gem duck type of adhesive material which is very generally used in the shoe industry. There it is customary to coat a fabric such as a strip of canvas with an adhesive composition and then to apply the freshly coated strip to the' inner sole of a shoe. Economy in the manufacturing operation requires that the canvas adhere immediately to the inner sole but the durability of the finished shoe necessitates a strong ultimate adhesion between the two surfaces. The former desirable result is obtained by using a thin adhesive layer which dries very quickly or is readily adsorbed by the contacting surfaces; but the latter ob jective necessitates the use of a relatively thick layer of adhesive which is frequently slow to dry and hence incompatible with an otherwise desirable instantaneous adhesion. My invention surmounts this difliculty by providing freshly prepared adhesive surface, a part of which is adapted immediately to adhere to another surface such as the inner sole of a shoe and another part of which contains a thicker layer of adhesive which is capable, when finally dried, of yielding a very strong adhesive bond. Many shoe cements may be described as plastic rather than viscous liquids and tend to resist lateral flow when compressed between two surfaces. I .take advantage of this resistance to lateral flow and find that the thick portions of the cement are not forced into the thin immediately adhesive layers when, for example, the freshly coated fabric is applied to an insole.

It will be apparent to those skilled in the art that my invention may be applied with advantage to any of the usual types of flexible sheet or base material such as paper, felt, woven fabric, etc. 'It is most advantageous for use, however. with a flexible base material which is both resilient and'absorptive in nature, for the application of viscous adhesives to base material of'this character and the adhesive attachment 01' such materials to other surfaces have presented the greatest difliculties according to prior methods.

It should be understood that the present disclosure is for the purpose of illustration only, and this invention includes all modifications and equivalents which fall within the scope of the appended claims.

I claim:

1. Process for the application of adhesive compositions to flexible sheet material which comprises depositing an adhesive composition on flexible sheet material and distributing the deposited adhesive composition over the said sheet material in a layer of unequal thickness so proportioned in relative depth of adhesive that the thin portions exhibit at once the tacky sticky property of adhesive while the thick portion retains its fluidity.

2. Process for adhesively attaching flexible sheet material to a surface which comprises depositing an adhesive composition on flexible sheet material, distributing the deposited adhesive composition over the said sheet material in stripes of unequal thickness, allowing the thin portions thereof to dry and contacting the thus distributed.

tacky adhesive layer with the surface to which the flexible sheet material is to be adhesively attached while the thick layer retains its fluidity.

to thickness that the thin portion is tacky while the thick portion is characterized by fluidity.

5. A reinforcement for insoles comprising a strip of fabric having a coating of adhesive applied to one surface thereof, the adhesive coating on certain areas of said strip being thicker than the adhesive coating on the remainder of said strip, whereby the areas of thin coating provide immediate adhesion and the areas of thick coating provide strong bonding.

6. That process of reinforcing insoles which includes the step of adhesively connecting a fabric reinforcement to the channeled side of said insole by means of an adhesive layer having alternately thick and thin portions, whereby the thin portions provide immediate adhesion and the thick portions provide strong bonding.

7. That process of securing rapid adhesion and subsequent permanent attachment of an insole reinforcement to an insole which includes applying an adhesive coat to said reinforcement, providing thin areas in said coat whereby the adhesive therein is rendered immediately tacky and adhesive, providing thickened areas of ad-. hesive thereby to provide a wear and flexure resistant bond and applying the coated reinforcement to the insole.

FRANK H. RUSSELL. 

